Communication method and apparatus

ABSTRACT

A communication method and an apparatus are provided. The method includes: obtaining, by a base station, power parameters of a first user equipment UE and an adjustment parameter δ1,ue1 for a first transmit power; sending, by the base station, the power parameters of the first UE and the adjustment parameter δ1,ue1 for the first transmit power to the first UE; determining, by the base station, the first transmit power according to the power parameters of the first UE and the adjustment parameter δ1,ue1 for the first transmit power; and sending, by the base station, a signal to the first UE at the first transmit power.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2014/095994, filed on Dec. 31, 2014, the disclosure of which ishereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to the communications field, and inparticular, to a communication method and an apparatus.

BACKGROUND

In an existing LTE (Long Term Evolution) system, an OFDMA (orthogonalfrequency division multiple access) technology is usually used fordownlink. To effectively promote cell-center and cell-edge throughputs,a NOMA (non-orthogonal multiple access) technology is a potentialcandidate technology. When the NOMA is used for communication, a basestation allocates different powers to different user equipments (UE).However, different UEs may use a same frequency resource.

Two or multiple UEs using a same time frequency resource block tocommunicate with a base station are referred to as paired UEs. Forexample, when using the NOMA technology, a UE1 and a UE2 use a same timefrequency resource block to communicate with a base station, and the UE2and the UE1 are paired UEs. The base station uses different transmitpowers to send signals to the UE1 and the UE2. There is interferencebetween a downlink signal for the UE1 and a downlink signal for the UE2.The downlink generally refers to a direction from a base station to aUE. To effectively extract the downlink signal for the UE1, the UE1needs to eliminate interference from the downlink signal for the UE2. Inthe prior art, the UE1 cannot obtain related information of the downlinksignal for the UE2, and cannot use the NOMA technology to communicate.

SUMMARY

Embodiments of the present invention provide a communication method andan apparatus, to implement communication by using a NOMA technology.

According to a first aspect, an embodiment of the present inventionprovides a base station, where the base station serves at least two userequipments UEs, the at least two UEs include a first UE and a second UE,and the base station includes: a processing unit, configured to obtainpower parameters of the first UE and an adjustment parameter δ_(1,ue1)for a first transmit power, where the power parameters of the first UEinclude a UE-specific parameter P_(A,ue) ₁ of the first UE, acell-specific parameter P_(B,ue) ₁ of the first UE, and a referencesignal transmit power of the first UE, and the first transmit power is atransmit power of downlink data for the first UE; and a sending unit,configured to send the power parameters of the first UE and theadjustment parameter δ_(1,ue1) for the first transmit power to the firstUE; where the processing unit is further configured to determine thefirst transmit power according to the power parameters of the first UEand the adjustment parameter δ_(1,ue1) for the first transmit power, andthe sending unit is further configured to send the downlink data for thefirst UE at the first transmit power.

According to a second aspect, an embodiment of the present inventionprovides a communication method, where the method is applied to acommunications network including at least two user equipments UEs, theat least two UEs include a first UE and a second UE, and the methodincludes: obtaining, by a base station, power parameters of the firstuser equipment UE and an adjustment parameter δ_(1,ue1) for a firsttransmit power, where the power parameters of the first UE include aUE-specific parameter P_(A,ue) ₁ of the first UE, a cell-specificparameter P_(B,ue) ₁ of the first UE, and a reference signal transmitpower of the first UE, and the first transmit power is a transmit powerof downlink data for the first UE; sending, by the base station, thepower parameters of the first UE and the adjustment parameter δ_(1,ue1)for the first transmit power to the first UE; determining, by the basestation, the first transmit power according to the power parameters ofthe first UE and the adjustment parameter δ_(1,ue1) for the firsttransmit power; and sending, by the base station, a downlink signal forthe first UE at the first transmit power.

According to a third aspect, an embodiment of the present inventionprovides a first user equipment UE, where the first UE communicates witha base station, the base station serves at least two UEs, the at leasttwo UEs include the first UE and a second UE, and the first UE includes:

a receiving unit, configured to receive power parameters of the first UEand an adjustment parameter δ_(1,ue1) for a first transmit power thatare sent by the base station, where the power parameters of the first UEinclude P_(A,ue) ₁ of the first UE, a cell-specific parameter P_(B,ue) ₁of the first UE, and a reference signal transmit power of the first UE,and the first transmit power is a transmit power of downlink data forthe first UE; and a processing unit, configured to: determine the firsttransmit power according to the power parameters of the first UE and theadjustment parameter δ_(1,ue1) for the first transmit power, anddetermine a second transmit power according to the power parameters ofthe first UE and the first transmit power, where the second transmitpower is a transmit power of downlink data for the second UE; where thereceiving unit is further configured to receive a signal sent by thebase station, where the received signal includes the downlink data forthe first UE; and the processing unit is further configured to obtain,according to the first transmit power and the second transmit power, thedownlink data for the first UE from the signal received by the receivingunit.

According to a fourth aspect, an embodiment of the present inventionprovides a communication method, where the method is applied to acommunications network including at least two user equipments UEs, theat least two UEs include a first UE and a second UE, and the methodincludes: receiving, by the first user equipment UE, power parameters ofthe first UE and an adjustment parameter δ_(1,ue1) for a first transmitpower that are sent by a base station, where the power parameters of thefirst UE include P_(A,ue) ₁ of the first UE, a cell-specific parameterP_(B,ue) ₁ of the first UE, and a reference signal transmit power of thefirst UE, and the first transmit power is a transmit power of downlinkdata for the first UE; determining, by the first UE, the first transmitpower according to the power parameters of the first UE and theadjustment parameter δ_(1,ue1) for the first transmit power;determining, by the first UE, a second transmit power according to thepower parameters of the first UE and the first transmit power, where thesecond transmit power is a transmit power of downlink data for thesecond UE; receiving, by the first UE, a signal sent by the basestation, where the received signal includes the downlink data for thefirst UE; and obtaining, by the first UE, the downlink data for thefirst UE from the received signal according to the first transmit powerand the second transmit power.

According to a fifth aspect, an embodiment of the present inventionprovides a base station, where the base station serves at least two userequipments UEs, the at least two UEs include a first UE and a second UE,and the base station includes: a processing unit, configured to obtainpower parameters of the first UE and power parameters of the second UE,where the power parameters of the first UE include a UE-specificparameter P_(A,ue) ₁ of the first UE, a cell-specific parameter P_(B,ue)₁ of the first UE, and a reference signal transmit power of the firstUE, and the power parameters of the second UE include a UE-specificparameter P_(A,ue) ₂ of the second UE, a cell-specific parameterP_(B,ue2) of the second UE, and a reference signal transmit power of thesecond UE; and a sending unit, configured to send the power parametersof the first UE and the power parameters of the second UE to the firstUE; where the processing unit is further configured to determine a firsttransmit power according to the power parameters of the first UE, wherethe first transmit power is a transmit power of downlink data for thefirst UE; and the sending unit is further configured to send thedownlink data for the first UE at the first transmit power.

According to a sixth aspect, an embodiment of the present inventionprovides a communication method, where the method is applied to acommunications network including at least two user equipments UEs, theat least two UEs include a first UE and a second UE, and the methodincludes: obtaining, by a base station, power parameters of the firstuser equipment UE and power parameters of the second UE, where the powerparameters of the first UE include a UE-specific parameter P_(A,ue) ₁ ofthe first UE, a cell-specific parameter P_(B,ue) ₁ of the first UE, anda reference signal transmit power of the first UE, and the powerparameters of the second UE includes a UE-specific parameter P_(A,ue) ₂of the second UE, a cell-specific parameter P_(B,ue2) of the second UE,and a reference signal transmit power of the second UE; sending, by thebase station, the power parameters of the first UE and the powerparameters of the second UE to the first UE; determining, by the basestation, a first transmit power according to the power parameters of thefirst UE, where the first transmit power is a transmit power of downlinkdata for the first UE; and sending, by the base station, the downlinkdata for the first UE at the first transmit power.

According to a seventh aspect, an embodiment of the present inventionprovides a first user equipment UE, where the first UE communicates witha base station, the base station serves at least two UEs, the at leasttwo UEs include the first UE and a second UE, and the first UE includes:a receiving unit, configured to receive power parameters of the first UEand power parameters of the second UE that are sent by the base station,where the power parameters of the first UE include a UE-specificparameter P_(A,ue) ₁ of the first UE, a cell-specific parameter P_(B,ue)₁ of the first UE, and a reference signal transmit power of the firstUE, and the power parameters of the second UE include a UE-specificparameter P_(A,ue) ₂ of the second UE, a cell-specific parameterP_(B,ue2) of the second UE, and a reference signal transmit power of thesecond UE; and a processing unit, configured to: determine a firsttransmit power according to the power parameters of the first UE, wherethe first transmit power is a transmit power of downlink data for thefirst UE; and determine a second transmit power according to the powerparameters of the second UE, where the second transmit power is atransmit power of downlink data for the second UE; where the receivingunit is further configured to receive a signal sent by the base station,where the received signal includes the downlink data for the first UE;and the processing unit is further configured to obtain, according tothe first transmit power and the second transmit power, the downlinkdata for the first UE from the signal received by the receiving unit.

According to an eighth aspect, an embodiment of the present inventionprovides a communication method, where the method is applied to acommunications network including at least two user equipments UEs, theat least two UEs include a first UE and a second UE, and the methodincludes: receiving, by the first UE, power parameters of the first UEand power parameters of the second UE that are sent by a base station,where the power parameters of the first UE include a UE-specificparameter P_(A,ue) ₁ of the first UE, a cell-specific parameter P_(B,ue)₁ of the first UE, and a reference signal transmit power of the firstUE, and the power parameters of the second UE include a UE-specificparameter P_(A,ue) ₂ of the second UE, a cell-specific parameterP_(B,ue2) of the second UE, and a reference signal transmit power of thesecond UE; determining, by the first UE, a first transmit poweraccording to the power parameters of the first UE, where the firsttransmit power is a transmit power of downlink data for the first UE;determining a second transmit power according to the power parameters ofthe second UE, where the second transmit power is a transmit power ofdownlink data for the second UE; receiving, by the first UE, a signalsent by the base station, where the received signal includes thedownlink data for the first UE; and obtaining, by the first UE, thedownlink data for the first UE from the received signal according to thefirst transmit power and the second transmit power.

In the embodiments of the present invention, the base station obtainsthe adjustment parameter δ_(1,ue1) for the first transmit power and thepower parameters of the first UE, and sends the adjustment parameterδ_(1,ue1) for the first transmit power and the power parameters of thefirst UE to the first UE. Therefore, the first UE may obtain the firsttransmit power according to the power parameters of the first userequipment UE, and determine the second transmit power according to theadjustment parameter δ_(1,ue1) for the first transmit power and thefirst transmit power. The first UE can eliminate interference from thedownlink data for the second UE according to the second transmit power,to implement communication by using a NOMA technology.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention more clearly, the following briefly describes the accompanyingdrawings required for describing the embodiments. Apparently, theaccompanying drawings in the following description show merely someembodiments of the present invention, and a person of ordinary skill inthe art may still derive other drawings from these accompanying drawingswithout creative efforts.

FIG. 1 is a schematic structural diagram of a network architectureaccording to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a base station according toEmbodiment 1 of the present invention;

FIG. 3 is a schematic structural diagram of a first UE according toEmbodiment 2 of the present invention;

FIG. 4 is a schematic structural diagram of a base station according toEmbodiment 3 of the present invention;

FIG. 5 is a schematic structural diagram of a first UE according toEmbodiment 6 of the present invention;

FIG. 6 is a schematic flowchart of a communication method according toEmbodiment 9 of the present invention;

FIG. 7 is a schematic flowchart of a communication method according toEmbodiment 10 of the present invention;

FIG. 8 is a schematic flowchart of a communication method according toEmbodiment 11 of the present invention; and

FIG. 9 is a schematic flowchart of a communication method according toEmbodiment 14 of the present invention.

DESCRIPTION OF EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present invention with reference to the accompanyingdrawings in the embodiments of the present invention. Apparently, thedescribed embodiments are merely some but not all of the embodiments ofthe present invention. All other embodiments obtained by a person ofordinary skill in the art based on the embodiments of the presentinvention without creative efforts shall fall within the protectionscope of the present invention.

A UE in the embodiments of the present invention may be, for example, acellular phone, a cordless phone, a SIP (Session Initiation Protocol)phone, a WLL (wireless local loop) station, a PDA (personal digitalassistant), a handheld device having a wireless communication function,an in-vehicle device, a wearable device, a computing device, or anotherprocessing device connected to a wireless modem.

A base station in the embodiments of the present invention may be, forexample, a device that communicates with a wireless terminal over an airinterface in an access network by using one or more sectors. The basestation may be configured to mutually convert a received over-the-airframe and an Internet Protocol (English: Internet Protocol, IP forshort) packet and serve as a router between the wireless terminal and aremaining portion of the access network. The remaining portion of theaccess network may include an IP network. The base station may furthercoordinate attribute management of the air interface. For example, thebase station may be a base station (EBase Transceiver Station, BTS forshort) in GSM (Global System for Mobile Communications) or CDMA (CodeDivision Multiple Access), or a base station (NodeB for short) in WCDMA(Wideband Code Division Multiple Access), or an evolved NodeB(Eevolutional Node B, NodeB or eNB or e-NodeB for short) in LTE, whichis not limited in the embodiments of the present invention.

The embodiments of the present invention disclose a communication methodand an apparatus. A base station notifies a first UE of relatedinformation of a first transmit power and a second transmit power. Thefirst UE obtains the related information of the first transmit power andthe second transmit power, so that the first UE eliminates interferencefrom downlink data for a second UE according to the related informationof the first transmit power and the second transmit power, to implementcommunication by using NOMA. The first transmit power is a transmitpower of downlink data for the first UE, and the second transmit poweris a transmit power of the downlink data for the second UE. Details areprovided in the following.

For ease of understanding of the present invention, a networkarchitecture used in the embodiments of the present invention is firstdescribed in the following. Referring to FIG. 1, FIG. 1 is a schematicstructural diagram of a network architecture according to an embodimentof the present invention. As shown in FIG. 1, the network includes abase station and UEs. There may be two or more UEs. Only a first UE anda second UE are displayed in the diagram. The first UE and the second UEuse a same time frequency resource block to communicate with the basestation, and a transmit power of downlink data for the first UE isdifferent from a transmit power of downlink data for the second UE. Thebase station is any base station in the embodiments of the presentinvention, and the first UE is any first UE in the embodiments of thepresent invention.

Based on the network architecture shown in FIG. 1, Embodiment 1 of thepresent invention discloses a base station. The base station serves atleast two UEs, and the at least two UEs include a first UE and a secondUE. Referring to FIG. 2, FIG. 2 is a schematic structural diagram of thebase station according to Embodiment 1 of the present invention. Asshown in FIG. 2, the base station includes a processing unit 201 and asending unit 202. The processing unit may be specifically a processor,and the sending unit may be specifically a transmitter.

The processing unit 201 is configured to obtain power parameters of thefirst UE and an adjustment parameter δ_(1,ue1) for a first transmitpower.

The sending unit 202 is configured to send the power parameters of thefirst UE and the adjustment parameter δ_(1,ue1) for the first transmitpower to the first UE.

The processing unit 201 is further configured to determine the firsttransmit power according to the power parameters of the first UE and theadjustment parameter δ_(1,ue1) for the first transmit power.

The sending unit 202 is further configured to send downlink data for thefirst UE at the first transmit power.

In this embodiment of the present invention, the power parameters of thefirst UE include a UE-specific parameter P_(A,ue) ₁ of the first UE, acell-specific parameter P_(B,ue) ₁ of the first UE, and a referencesignal transmit power of the first UE. The first transmit power is atransmit power of the downlink data for the first UE.

In an optional implementation, P_(A,ue) ₁ is a UE-specific parameter, ofthe first UE, provided by a first higher layer, and P_(B,ue) ₁ is acell-specific parameter, of the first UE, provided by the first higherlayer. The first higher layer is a higher layer of the first UE, and maybe a base station for the first UE or another network entity. Fordifferent UEs in a same cell, P_(A) may vary while P_(B) as well as areference signal transmit power remains the same.

In an optional implementation, the sending unit 202 is specificallyconfigured to send the power parameters of the first UE and theadjustment parameter δ_(1,ue1) for the first transmit power to the firstUE by using higher layer signaling or by using downlink controlinformation (DCI) in a physical downlink control channel (PDCCH).

In an optional implementation, the adjustment parameter δ_(1,ue1) forthe first transmit power is an adjustment value for the first transmitpower. The processing unit 201 is specifically configured to determine athird transmit power according to the power parameters of the first UE.The first transmit power is obtained after the adjustment value for thefirst transmit power is subtracted from or added to the third transmitpower.

In an optional implementation, the processing unit 201 is specificallyconfigured to: determine ρ_(ue1) according to P_(A,ue) ₁ and P_(B,ue) ₁, and determine the third transmit power according to ρ_(ue1) and thereference signal transmit power of the first UE. ρ_(ue1) indicates aratio of energy per resource element EPRE of a physical downlink sharedchannel PDSCH of the first UE to EPRE of a cell-specific referencesignal of the first UE, ρ_(ue1) includes ρ_(A,ue1) and ρ_(B,ue1), andρ_(A,ue1) and ρ_(B,ue1) correspond to different orthogonal frequencydivision multiplexing OFDM symbol indexes of the first UE.

In an optional implementation, the OFDM symbol indexes corresponding toρ_(A,ue1) and ρ_(B,ue1) are shown in Table 1 or Table 2.

TABLE 1 An OFDM symbol index used An OFDM symbol index by ρ_(A,ue1) inused by A quantity a timeslot ρ_(B,ue1) in a timeslot of antenna NormalExtended Normal Extended cyclic ports cyclic prefix cyclic prefix cyclicprefix prefix 1 or 2 1, 2, 3, 5, 6 1, 2, 4, 5 0, 4 0, 3 4 2, 3, 5, 6 2,4, 5 0, 1, 4 0, 1, 3

TABLE 2 An OFDM symbol index used by An OFDM symbol index used Aρ_(A,ue1) in a timeslot by ρ_(B,ue1) in a timeslot quantity Normalcyclic Extended Normal cyclic Extended of prefix cyclic prefix prefixcyclic prefix antenna n_(s) mod n_(s) mod n_(s) mod n_(s) mod n_(s) modn_(s) mod n_(s) mod n_(s) mod ports 2 = 0 2 = 1 2 = 0 2 = 1 2 = 0 2 = 12 = 0 2 = 1 1 or 2 1, 2, 3, 0, 1, 2, 1, 2, 3, 0, 1, 2, 0 — 0 — 4, 5, 63, 4, 5, 6 4, 5 3, 4, 5 4 2, 3, 4, 0, 1, 2, 2, 4, 3, 5 0, 1, 2, 0, 1 —0, 1 — 5, 6 3, 4, 5, 6 3, 4, 5

n_(s) indicates a slot index (in a radio frame.

In an optional implementation, when determining the third transmitpower, the processing unit 201 is specifically configured to determineρ_(A,ue1) according to the following formulas:

$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power}\text{-}{offset}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \begin{matrix}{{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\;} \\{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}\end{matrix} \\{\delta_{{power}\text{-}{offset}} + P_{A,{{ue}\; 1}}} & \begin{matrix}{{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\mspace{45mu}} \\{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}\end{matrix}\delta_{{power}\text{-}{offset}}} = \left\{ {\begin{matrix}{{- 10}{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The processing unit 201 is specifically configured to determineρ_(B,ue1) according to ρ_(A,ue1) and Table 3.

TABLE 3 ρ_(B,ue1)/ρ_(A,ue1) P_(B,ue1) One antenna port Two or fourantenna port 0 1 5/4 1 4/5 1 2 3/5 3/4 3 2/5 1/2

In an optional implementation, the sending unit 202 is furtherconfigured to use a downlink power offset field in DCI in a PDCCH of thefirst UE to indicate δ_(power-offset). The downlink power offset fieldmay occupy one bit. The first UE learns of δ_(power-offset) by using thedownlink power offset field. For example, the downlink power offsetfield may be shown in the following Table 4.

TABLE 4 Downlink power offset field δ_(power-offset) [dB] 0 −10log₁₀(2)1 0

In an optional implementation, the processing unit 201 determinesρ_(ue1) according to P_(A,ue) ₁ , P_(B,ue) ₁ , and the adjustmentparameter δ_(1,ue1) for the first transmit power, and determines thefirst transmit power according to ρ_(ue1) and the reference signaltransmit power of the first UE. ρ_(ue1) indicates a ratio of energy perresource element EPRE of a physical downlink shared channel PDSCH of thefirst UE to EPRE of a cell-specific reference signal of the first UE,ρ_(ue1) includes ρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1)correspond to different orthogonal frequency division multiplexing OFDMsymbol indexes of the first UE.

In an optional implementation, the processing unit 201 is specificallyconfigured to determine ρ_(A,ue1) according to the following formulas:

$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power}\text{-}{offset}} + \delta_{1,{{ue}\; 1}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \begin{matrix}{{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\mspace{11mu}} \\{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}\end{matrix} \\{\delta_{{power}\text{-}{offset}} + \delta_{1,{{ue}\; 1}} + P_{A,{{ue}\; 1}}} & \begin{matrix}{{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\mspace{45mu}} \\{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}\end{matrix}\delta_{{power}\text{-}{offset}}} = \left\{ {\begin{matrix}{{- 10}{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The processing unit 201 is specifically configured to determineρ_(B,ue1) according to ρ_(A,ue1) and Table 3.

In another optional implementation, the processing unit 201 is furtherconfigured to determine a second transmit power according to the powerparameters of the first UE and the first transmit power. The secondtransmit power is a transmit power of downlink data for the second UE.The sending unit 202 is further configured to send a signal to thesecond UE at the second transmit power.

In an optional implementation, the processing unit 201 is specificallyconfigured to determine the second transmit power according to the thirdtransmit power and the first transmit power. The third transmit power isdetermined according to the power parameters of the first UE. For aspecific implementation of determining, refer to the foregoingdescriptions.

In an optional implementation, the second transmit power is a differencebetween the third transmit power and the first transmit power.

In Embodiment 1 of the present invention, the processing unit 201 of thebase station obtains the adjustment parameter δ_(1,ue1) for the firsttransmit power and the power parameters of the first UE, and sends theadjustment parameter δ_(1,ue1) for the first transmit power and thepower parameters of the first UE to the first UE by using the sendingunit 202. Therefore, the first UE may obtain the first transmit poweraccording to the power parameters of the first user equipment UE, anddetermine the second transmit power according to the adjustmentparameter δ_(1,ue1) for the first transmit power and the first transmitpower. The first UE can eliminate interference from the downlink datafor the second UE according to the second transmit power, to implementcommunication by using a NOMA technology. The processing unit 201 of thebase station obtains the adjustment parameter δ_(1,ue1) for the firsttransmit power, and sends the adjustment parameter δ_(1,ue1) for thefirst transmit power to the first UE by using the sending unit 202. Thebase station schedules the first transmit power by using the adjustmentparameter δ_(1,ue1) for the first transmit power, so that dynamicscheduling of a transmit power in the NOMA technology is implemented.

Embodiment 1 may be applied to a scenario in which a power parameterP_(A,ue) ₁ of a first UE is same as a power parameter P_(A,ue) ₂ of asecond UE. P_(A,ue) ₂ is a UE-specific parameter, of the second UE,provided by a second higher layer. The second higher layer is a higherlayer of the second UE, and may be, for example, a base station for thesecond UE. In this scenario, because the power parameter P_(A,ue) ₁ ofthe first UE is same as the power parameter P_(A,ue) ₂ of the second UE,it may be considered that transmit powers determined respectivelyaccording to power parameters of the first UE and power parameters ofthe second UE are the same. Therefore, the first UE may obtain thesecond transmit power according to the power parameters of the first UE.The base station sends the power parameters of the first UE to the firstUE, and the first UE can eliminate interference from a signal for thesecond UE according to the second transmit power, to implementcommunication by using the NOMA technology.

Based on the network architecture shown in FIG. 1, Embodiment 2 of thepresent invention further discloses a first UE. The first UEcommunicates with a base station. The base station serves at least twoUEs, and the at least two UEs include the first UE and a second UE. FIG.3 is a schematic structural diagram of the first UE according toEmbodiment 2 of the present invention. As shown in FIG. 3, the first UEincludes a receiving unit 301 and a processing unit 302. The receivingunit may be specifically a receiver, and the processing unit may bespecifically a processor.

The receiving unit 301 is configured to receive power parameters of thefirst UE and an adjustment parameter δ_(1,ue1) for a first transmitpower that are sent by the base station. The power parameters of thefirst UE include P_(A,ue) ₁ of the first UE, a cell-specific parameterP_(B,ue) ₁ of the first UE, and a reference signal transmit power of thefirst UE, and the first transmit power is a transmit power of downlinkdata for the first UE.

The processing unit 302 is configured to: determine the first transmitpower according to the power parameters of the first UE and theadjustment parameter δ_(1,ue1) for the first transmit power, anddetermine a second transmit power according to the power parameters ofthe first UE and the first transmit power. The second transmit power isa transmit power of downlink data for the second UE.

The receiving unit 301 is further configured to receive a signal sent bythe base station, and the received signal includes the downlink data forthe first UE.

The processing unit 302 is further configured to obtain, according tothe first transmit power and the second transmit power, the downlinkdata for the first UE from the signal received by the receiving unit.

For specific meanings of these related parameters in this embodiment ofthe present invention, refer to descriptions in Embodiment 1.

In an optional implementation, the receiving unit 301 is specificallyconfigured to receive the power parameters of the first UE and theadjustment parameter δ_(1,ue1) for the first transmit power that aresent by the base station by using higher layer signaling or by using DCIin a PDCCH.

In an optional implementation, the adjustment parameter δ_(1,ue1) forthe first transmit power is an adjustment value for the first transmitpower. The processing unit 302 is specifically configured to determine athird transmit power according to the power parameters of the first UE.The first transmit power is obtained after the adjustment value for thefirst transmit power is subtracted from or added to the third transmitpower.

In another optional implementation, the processing unit 302 isspecifically configured to: determine ρ_(ue1) according to P_(A,ue) ₁and P_(B,ue) ₁ , and determine the third transmit power according toρ_(ue1) and the reference signal transmit power of the first UE. ρ_(ue1)indicates a ratio of energy per resource element EPRE of a physicaldownlink shared channel PDSCH of the first UE to EPRE of a cell-specificreference signal of the first UE, ρ_(ue1) includes ρ_(A,ue1) andρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1) correspond to differentorthogonal frequency division multiplexing OFDM symbol indexes of thefirst UE. For descriptions of these related parameters, refer toEmbodiment 1.

In an optional implementation, when determining the third transmitpower, the processing unit 302 is specifically configured to determineρ_(A,ue1) according to the following formulas:

$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The processing unit 302 is specifically configured to determineρ_(B,ue1) according to ρ_(A,ue1) and Table 3.

In an optional implementation, the sending unit 301 is furtherconfigured to receive an indication δ_(power-offset) sent by the basestation by using a downlink power offset field in DCI in a PDCCH of thefirst UE. The downlink power offset field may occupy one bit. Forexample, the downlink power offset field may be shown in the followingTable 4.

In an optional implementation, the processing unit 302 is furtherconfigured to determine ρ_(ue1) according to P_(A,ue) ₁ , P_(B,ue) ₁ ,and the adjustment parameter δ_(1,ue1) for the first transmit power, anddetermine the first transmit power according to ρ_(ue1) and thereference signal transmit power of the first UE. ρ_(ue1) indicates aratio of energy per resource element EPRE of a physical downlink sharedchannel PDSCH of the first UE to EPRE of a cell-specific referencesignal of the first UE, ρ_(ue1) includes ρ_(A,ue1) and ρ_(B,ue1), andρ_(A,ue1) and ρ_(B,ue1) correspond to different orthogonal frequencydivision multiplexing OFDM symbol indexes of the first UE.

In an optional implementation, the processing unit 302 is specificallyconfigured to determine ρ_(A,ue1) according to the following formulas:

$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The processing unit 302 is specifically configured to determineρ_(B,ue1) according to ρ_(A,ue1) and Table 3.

In an optional implementation, the processing unit 302 is furtherconfigured to determine a second transmit power according to the powerparameters of the first UE and the first transmit power. The secondtransmit power is a transmit power of downlink data for the second UE.

In an optional implementation, the processing unit 302 is specificallyconfigured to determine the second transmit power according to the thirdtransmit power and the first transmit power. The third transmit power isdetermined according to the power parameters of the first UE. For aspecific implementation of determining, refer to the foregoingdescriptions.

In an optional implementation, the second transmit power is a differencebetween the third transmit power and the first transmit power.

In an optional implementation, when the first UE obtains the downlinkdata for the first UE, the first UE needs to use an advanced receiver,such as a maximum likelihood (ML) receiver or a codeword interferencecancellation (CWIC) receiver.

When using the maximum likelihood receiver, the first UE may matchpossible candidate downlink signals of the first UE and the second UEagainst the received signal, and determine soft information of a bitcorresponding to a downlink signal for the first UE. Generally, adownlink signal for the second UE is an interference signal for thefirst UE. Effectively designing constellation diagrams of the first UEand the second UE may increase a distance of the bit corresponding tothe downlink signal for the first UE to an equal effect, so thattransmission reliability is promoted. For example, a compoundconstellation diagram of the first UE and the second UE conforms to Graymapping or the like. The downlink signal for the first UE carries thedownlink data for the first UE.

When using the CWIC receiver, the first UE first obtains a downlinksignal for the second UE by means of demodulation, and then obtains adownlink signal for the first UE by subtracting the downlink signal forthe second UE from the received signal.

The second UE may consider a downlink signal for the first UE asinterference, and directly use an existing common receiver.

For example, it is assumed that a channel coefficient corresponding tothe first UE is H₁, and noise interference is σ₁. A channel coefficientcorresponding to the second UE is H₂, and noise interference is σ₂. Thebase station sends a downlink signal X₁ for the first UE by using afirst transmit power P₁, and the base station sends a downlink signal X₂for the second UE on a same time frequency resource by using a secondtransmit power P₂. In this case, signals received by the first UE andthe second UE are respectively Y₁ and Y₂, which are respectivelyindicated as:Y ₁=√{square root over (P ₁)}H ₁ X ₁+√{square root over (P ₂)}H ₁ X ₂+σ₁Y ₂=√{square root over (P ₁)}H ₂ X ₁+√{square root over (P ₂)}H ₂ X₂+σ₂.

The first UE receives the receiving signal Y₁, and first obtains thechannel H₁ and the interference σ₁ respectively by using channelestimation and noise estimation. Then the first UE obtains the downlinksignal X₂ for the second UE at first. Finally, the first UE may obtainthe downlink signal X₁ for the first UE according to the foregoingformulas.

It should be noted that, in the foregoing process of resolving thedownlink signal X₁ for the first UE, the first UE can first resolve X₂,and then subtract X₂ to obtain more accurately estimated X₁, and this isbecause a signal-to-noise ratio of the first UE is higher than that ofthe second UE. Therefore, the first UE can correctly resolve thedownlink signal X₂ for the second UE. For the second UE, because thedownlink signal X₁ for the second UE cannot be correctly resolved, X₂ isdirectly resolved only according to the following formula:Y ₂=√{square root over (P ₂)}H ₂ X ₂+(√{square root over (P ₁)}H ₂ X₁+σ₂).

In Embodiment 2 of the present invention, the receiving unit 301 of thefirst UE receives the power parameters of the first UE and theadjustment parameter δ_(1,ue1) for the first transmit power that aresent by the base station. The processing unit 302 of the first UEobtains the first transmit power according to the power parameters ofthe first user equipment UE, and determines the second transmit poweraccording to the power parameters of the first UE and the first transmitpower. The first UE can eliminate interference from a signal for thesecond UE according to the second transmit power, to implementcommunication by using a NOMA technology.

Embodiment 2 of the present invention may be applied to a scenario inwhich a power parameter P_(A,ue) ₁ of a first UE is same as a powerparameter P_(A,ue) ₂ of a second UE. P_(A,ue) ₂ is a UE-specificparameter, of the second UE, provided by a second higher layer. Thesecond higher layer is a higher layer of the second UE, and may be, forexample, a base station for the second UE. In this scenario, because thepower parameter P_(A,ue) ₁ of the first UE is same as the powerparameter P_(A,ue) ₂ of the second UE, it may be considered thattransmit powers determined respectively according to power parameters ofthe first UE and power parameters of the second UE are the same.Therefore, the first UE may obtain the second transmit power accordingto the power parameters of the first UE. The base station sends thepower parameters of the first UE to the first UE, and the first UE caneliminate interference from a signal for the second UE according to thesecond transmit power, to implement communication by using the NOMAtechnology.

Based on the network architecture shown in FIG. 1, Embodiment 3 of thepresent invention further discloses a base station. The base stationserves at least two UEs, and the at least two UEs include a first UE anda second UE. Referring to FIG. 4, FIG. 4 is a schematic structuraldiagram of the base station according to Embodiment 3 of the presentinvention. As shown in FIG. 4, the base station includes a processingunit 401 and a sending unit 402. The processing unit may be specificallya processor, and the sending unit may be specifically a transmitter.

The processing unit 401 is configured to obtain power parameters of thefirst UE and power parameters of the second UE. The power parameters ofthe first UE include a UE-specific parameter P_(A,ue) ₁ of the first UE,a cell-specific parameter P_(B,ue) ₁ of the first UE, and a referencesignal transmit power of the first UE, and the power parameters of thesecond UE include a UE-specific parameter P_(A,ue) ₂ of the second UE, acell-specific parameter P_(B,ue2) of the second UE, and a referencesignal transmit power of the second UE.

The sending unit 402 is configured to send the power parameters of thefirst UE and the power parameters of the second UE to the first UE.

The processing unit 401 is further configured to determine a firsttransmit power according to the power parameters of the first UE, andthe first transmit power is a transmit power of downlink data for thefirst UE.

The sending unit 402 is further configured to send the downlink data forthe first UE at the first transmit power.

For meanings of the power parameters of the first UE in this embodimentof the present invention, refer to Embodiment 1.

P_(A,ue) ₂ is a UE-specific parameter, of the second UE, provided by asecond higher layer, and P_(B,ue2) is a cell-specific parameter, of thesecond UE, provided by the second higher layer. The second higher layeris a higher layer of the second UE, and may be a base station for thesecond UE or another network entity. For different UEs in a same cell,P_(A) may vary while P_(B) as well as a reference signal transmit powerremains the same.

In an optional implementation, the sending unit is specificallyconfigured to send the power parameters of the first UE and the powerparameters of the second UE to the first UE by using higher layersignaling or by using DCI in a PDCCH.

In an optional implementation, the processing unit 401 determinesρ_(ue1) according to P_(A,ue) ₁ and P_(B,ue) ₁ , and determines thefirst transmit power according to ρ_(ue1) and the reference signaltransmit power of the first UE. ρ_(ue1) indicates a ratio of energy perresource element EPRE of a physical downlink shared channel PDSCH of thefirst UE to EPRE of a cell-specific reference signal of the first UE,ρ_(ue1) includes ρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1)correspond to different orthogonal frequency division multiplexing OFDMsymbol indexes of the first UE.

In an optional implementation, the processing unit 401 specificallydetermines ρ_(A,ue1) according to the following formulas:

$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The processing unit 401 is specifically configured to determineρ_(B,ue1) according to ρ_(A,ue1) and Table 3.

In an optional implementation, the sending unit 402 is furtherconfigured to use a downlink power offset field in DCI in a PDCCH of thefirst UE to indicate δ_(power-offset). The downlink power offset fieldmay occupy one bit. The first UE learns of δ_(power-offset) by using thedownlink power offset field. For example, the downlink power offsetfield may be shown in the following Table 4.

In an optional implementation, the processing unit 401 is furtherconfigured to determine a second transmit power according to the powerparameters of the second UE. The second transmit power is a transmitpower of downlink data for the second UE. The sending unit 402 isfurther configured to send the downlink data for the second UE at thesecond transmit power.

In an optional implementation, the processing unit 402 is specificallyconfigured to: determine ρ_(ue2) according to P_(A,ue) ₂ and P_(B,ue2),and determine the second transmit power according to ρ_(ue2) and thereference signal transmit power of the second UE. ρ_(ue2) indicates aratio of energy per resource element EPRE of a physical downlink sharedchannel PDSCH of the second UE to EPRE of a cell-specific referencesignal of the second UE, ρ_(ue2) includes ρ_(A,ue2) and ρ_(B,ue2), andρ_(A,ue2) and ρ_(B,ue2) correspond to different orthogonal frequencydivision multiplexing OFDM symbol indexes of the second UE.

In an optional implementation, the OFDM symbol indexes corresponding toρ_(A,ue2) and ρ_(B,ue2) are shown in Table 5 or Table 6.

TABLE 5 An OFDM symbol index used by An OFDM symbol index used Aquantity ρ_(A,ue2) in a timeslot by ρ_(B,ue2) in a timeslot of antennaNormal Extended Normal Extended cyclic ports cyclic prefix cyclic prefixcyclic prefix prefix 1 or 2 1, 2, 3, 5, 6 1, 2, 4, 5 0, 4 0, 3 4 2, 3,5, 6 2, 4, 5 0, 1, 4 0, 1, 3

TABLE 6 An OFDM symbol index used by An OFDM symbol index used by Aρ_(A,ue2) in a timeslot ρ_(B,ue2) in a timeslot quantity Normal cyclicExtended cyclic Normal cyclic Extended cyclic of prefix prefix prefixprefix antenna n_(s) mod n_(s) mod n_(s) mod n_(s) mod n_(s) mod n_(s)mod n_(s) mod n_(s) mod ports 2 = 0 2 = 1 2 = 0 2 = 1 2 = 0 2 = 1 2 = 02 = 1 1 or 2 1, 2, 3, 4, 0, 1, 2, 3, 1, 2, 3, 4, 5 0, 1, 2, 3, 0 — 0 —5, 6 4, 5, 6 4, 5 4 2, 3, 4, 5, 6 0, 1, 2, 3, 2, 4, 3, 5 0, 1, 2, 3, 0,1 — 0, 1 — 4, 5, 6 4, 5

n_(s) indicates a slot index in a radio frame.

In an optional implementation, the processing unit 402 is specificallyconfigured to determine ρ_(A,ue2) according to the following formulas:

$\rho_{A,{{ue}\; 2}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + P_{A,{{ue}\; 2}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + P_{A,{{ue}\; 2}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The processing unit 402 is specifically configured to determineρ_(B,ue2) according to ρ_(A,ue2) and Table 3.

In Embodiment 3 of the present invention, the processing unit 401 of thebase station obtains the power parameters of the first UE and the powerparameters of the second UE, and sends the power parameters of the firstUE and the power parameters of the second UE to the first UE by usingthe sending unit 402, so that the first UE may obtain the first transmitpower according to the power parameters of the first UE, and determinethe second transmit power according to the power parameters of thesecond UE. The first UE can eliminate interference from a signal for thesecond UE according to the second transmit power, to implementcommunication by using a NOMA technology.

Embodiment 4 of the present invention further discloses a base station.A difference between Embodiment 4 and Embodiment 3 lies in that theprocessing unit 401 is further configured to obtain an adjustmentparameter δ_(1,ue1) for the first transmit power, and the sending unit402 is further configured to send the adjustment parameter δ_(1,ue1) forthe first transmit power to the first UE. For meanings of these relatedparameters, refer to Embodiment 1.

In an optional implementation, the sending unit 402 is specificallyconfigured to send the adjustment parameter δ_(1,ue1) for the firsttransmit power to the first UE by using higher layer signaling or byusing DCI in a PDCCH.

In this embodiment, the processing unit 401 is specifically configuredto determine the first transmit power according to the power parametersof the first UE and the adjustment parameter δ_(1,ue1) for the firsttransmit power.

In an optional implementation, the adjustment parameter δ_(1,ue1) forthe first transmit power is an adjustment value for the first transmitpower. The processing unit 401 is specifically configured to determine athird transmit power according to the power parameters of the first UE.The first transmit power is obtained after the adjustment value for thefirst transmit power is subtracted from or added to the third transmitpower. For a manner of determining the third transmit power by theprocessing unit 401, refer to processing by the processing unit 201 inEmbodiment 1. Details are not described herein again.

In an optional implementation, the processing unit 401 is specificallyconfigured to determine ρ_(ue1) according to P_(A,ue) ₁ , P_(B,ue) ₁ ,and the adjustment parameter δ_(1,ue1) for the first transmit power, anddetermine the first transmit power according to ρ_(ue1) and thereference signal transmit power of the first UE. ρ_(ue1) indicates aratio of energy per resource element EPRE of a physical downlink sharedchannel PDSCH of the first UE to EPRE of a cell-specific referencesignal of the first UE, ρ_(ue1) includes ρ_(A,ue1) and ρ_(B,ue1), andρ_(A,ue1) and ρ_(B,ue1) correspond to different orthogonal frequencydivision multiplexing OFDM symbol indexes of the first UE. For aspecific process for determining ρ_(A,ue1) and ρ_(B,ue1) by theprocessing unit 401, refer to descriptions of the processing unit 201 inEmbodiment 1.

In Embodiment 4 of the present invention, the processing unit 401 of thebase station obtains the adjustment parameter δ_(1,ue1) for the firsttransmit power, and sends the adjustment parameter δ_(1,ue1) for thefirst transmit power to the first UE by using the sending unit 402. Thebase station schedules the first transmit power by using the adjustmentparameter δ_(1,ue1) for the first transmit power, so that dynamicscheduling of a transmit power in the NOMA technology is implemented.

Embodiment 5 of the present invention further discloses a base station.A difference between Embodiment 5 and Embodiment 3 or Embodiment 4 liesin that the processing unit 401 is further configured to obtain anadjustment parameter δ_(1,ue2) for the second transmit power, and thesending unit 402 is further configured to send the adjustment parameterδ_(1,ue2) for the second transmit power to the first UE.

In an optional implementation, the sending unit 402 is specificallyconfigured to send the adjustment parameter δ_(1,ue2) for the secondtransmit power to the first UE by using higher layer signaling or byusing DCI in a PDCCH.

In an optional implementation, the processing unit 401 is furtherconfigured to determine the second transmit power according to the powerparameters of the second UE and the adjustment parameter δ_(1,ue2) forthe second transmit power. The sending unit 402 is further configured tosend the downlink data for the second UE at the second transmit power.

In an optional implementation, the adjustment parameter δ_(1,ue2) forthe second transmit power is an adjustment value for the second transmitpower. The processing unit 401 is specifically configured to determine afourth transmit power according to the power parameters of the secondUE. The second transmit power is obtained after the adjustment value forthe second transmit power is subtracted from or added to the fourthtransmit power.

In an optional implementation, the processing unit 401 is specificallyconfigured to: determine ρ_(ue2) according to P_(A,ue2) and P_(B,ue2),and determine the fourth transmit power according to ρ_(ue2) and thereference signal transmit power of the second UE. ρ_(ue2) indicates aratio of energy per resource element EPRE of a physical downlink sharedchannel PDSCH of the second UE to EPRE of a cell-specific referencesignal of the second UE, ρ_(ue2) includes ρ_(A,ue2) and ρ_(B,ue2), andρ_(A,ue2) and ρ_(B,ue2) correspond to different orthogonal frequencydivision multiplexing OFDM symbol indexes of the second UE.

In an optional implementation, for meanings of ρ_(A,ue2) and ρ_(B,ue2)for determining the fourth transmit power, refer to Embodiment 3. For adetermining manner of ρ_(A,ue2) and ρ_(B,ue2) refer to descriptions inEmbodiment 3. Details are not described herein again.

In another optional implementation, the processing unit 401 isspecifically configured to determine ρ_(ue2) according to P_(A,ue) ₂ ,P_(B,ue) ₂ , and the adjustment parameter δ_(1,ue2) for the secondtransmit power, and determine the second transmit power according toρ_(ue2) and the reference signal transmit power of the second UE.ρ_(ue2) indicates a ratio of energy per resource element EPRE of aphysical downlink shared channel PDSCH of the second UE to EPRE of acell-specific reference signal of the second UE, ρ_(ue2) includesρ_(A,ue2) and ρ_(B,ue2), and ρ_(A,ue2) and ρ_(B,ue2) correspond todifferent orthogonal frequency division multiplexing OFDM symbol indexesof the second UE.

In an implementation, the processing unit 401 is specifically configuredto determine ρ_(A,ue2) according to the following formulas:

$\rho_{A,{{ue}\; 2}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + P_{A,{{ue}\; 2}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + P_{A,{{ue}\; 2}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The processing unit 401 is specifically configured to determineρ_(B,ue2) according to ρ_(A,ue2) and Table 3.

In Embodiment 5 of the present invention, the processing unit 401 of thebase station obtains the adjustment parameter δ_(1,ue2) for the secondtransmit power, and sends the adjustment parameter δ_(1,ue2) for thesecond transmit power to the first UE by using the sending unit 402. Thebase station schedules the transmit power by using the adjustmentparameter δ_(1,ue2) for the second transmit power, so that dynamicscheduling of a transmit power in the NOMA technology is implemented.

Based on the network architecture shown in FIG. 1, Embodiment 6 of thepresent invention further discloses a first UE. The first UEcommunicates with a base station. The base station serves at least twoUEs, and the at least two UEs include the first UE and a second UE. FIG.5 is a schematic structural diagram of the first UE according toEmbodiment 6 of the present invention. As shown in FIG. 7, the first UEincludes a receiving unit 501 and a processing unit 502. The receivingunit may be specifically a receiver, and the processing unit may bespecifically a processor.

The receiving unit 501 is configured to receive power parameters of thefirst UE and power parameters of the second UE that are sent by the basestation.

The power parameters of the first UE include a UE-specific parameterP_(A,ue) ₁ of the first UE, a cell-specific parameter P_(B,ue) ₁ of thefirst UE, and a reference signal transmit power of the first UE. Thepower parameters of the second UE include a UE-specific parameterP_(A,ue) ₂ of the second UE, a cell-specific parameter P_(B,ue2) of thesecond UE, and a reference signal transmit power of the second UE. Forspecific meanings of these parameters, refer to descriptions inEmbodiment 3.

The processing unit 502 is configured to: determine a first transmitpower according to the power parameters of the first UE, where the firsttransmit power is a transmit power of downlink data for the first UE;and determine a second transmit power according to the power parametersof the second UE, where the second transmit power is a transmit power ofdownlink data for the second UE.

The receiving unit 501 is further configured to receive a signal sent bythe base station, and the received signal includes the downlink data forthe first UE.

The processing unit 502 is further configured to obtain, according tothe first transmit power and the second transmit power, the downlinkdata for the first UE from the signal received by the receiving unit.

In an optional implementation, the receiving unit 501 is specificallyconfigured to receive the power parameters of the first UE and the powerparameters of the second UE that are sent by the base station by usinghigher layer signaling or by using DCI in a PDCCH.

In an optional implementation, the processing unit 502 is specificallyconfigured to: determine ρ_(ue1) according to P_(A,ue) ₁ and P_(B,ue) ₁, and determine the first transmit power according to ρ_(ue1) and thereference signal transmit power of the first UE. ρ_(ue1) indicates aratio of energy per resource element EPRE of a physical downlink sharedchannel PDSCH of the first UE to EPRE of a cell-specific referencesignal of the first UE, ρ_(ue1) includes ρ_(A,ue1) and ρ_(B,ue1), andρ_(A,ue1) and ρ_(B,ue1) correspond to different orthogonal frequencydivision multiplexing OFDM symbol indexes of the first UE. A specificprocess is the same as the manner for determining the first transmitpower by the processing unit 401 in Embodiment 3. For correspondingdescriptions, refer to Embodiment 3. Details are not described hereinagain.

The processing unit 502 is further configured to determine the secondtransmit power according to the power parameters of the second UE.

In an optional implementation, the processing unit 502 is specificallyconfigured to: determine ρ_(ue2) according to P_(A,ue2) and P_(B,ue2),and determine the second transmit power according to ρ_(ue2) and thereference signal transmit power of the second UE. ρ_(ue2) indicates aratio of energy per resource element EPRE of a physical downlink sharedchannel PDSCH of the second UE to EPRE of a cell-specific referencesignal of the second UE, ρ_(ue2) includes ρ_(A,ue2) and ρ_(B,ue2), andρ_(A,ue2) and ρ_(B,ue2) correspond to different orthogonal frequencydivision multiplexing OFDM symbol indexes of the second UE. A specificprocess is the same as the manner for determining the second transmitpower by the processing unit 401 in Embodiment 3. For correspondingdescriptions, refer to Embodiment 3. Details are not described hereinagain.

In Embodiment 6 of the present invention, the receiving unit of thefirst UE receives the power parameters of the first UE and the powerparameters of the second UE that are sent by the base station. Theprocessing unit of the first UE may obtain the first transmit poweraccording to the power parameters of the first UE, and determine thesecond transmit power according to the power parameters of the secondUE. The first UE can eliminate interference from the downlink data forthe second UE according to the second transmit power, to implementcommunication by using a NOMA technology.

Embodiment 7 of the present invention further discloses a first UE. Adifference between Embodiment 7 and Embodiment 6 lies in that thereceiving unit 501 is further configured to receive an adjustmentparameter δ_(1,ue1), for the first transmit power, sent by the basestation. The processing unit 502 is specifically configured to determinethe first transmit power according to the power parameters of the firstUE and the adjustment parameter δ_(1,ue1) for the first transmit power.

In an optional implementation, the receiving unit 501 is specificallyconfigured to receive the adjustment parameter δ_(1,ue1), for the firsttransmit power, sent by the base station by using higher layer signalingor by using downlink control information DCI in a physical downlinkcontrol channel PDCCH.

In an optional implementation, the adjustment parameter δ_(1,ue1) forthe first transmit power is an adjustment value for the first transmitpower. The processing unit 502 is specifically configured to determine athird transmit power according to the power parameters of the first UE.The first transmit power is obtained after the adjustment value for thefirst transmit power is subtracted from or added to the third transmitpower. For a manner of determining the third transmit power by theprocessing unit 502, refer to processing by the processing unit 302 inEmbodiment 2. Details are not described herein again.

In an optional implementation, the processing unit 502 is specificallyconfigured to determine ρ_(ue1) according to P_(A,ue) ₁ , P_(B,ue) ₁ ,and the adjustment parameter δ_(1,ue1) for the first transmit power, anddetermine the first transmit power according to ρ_(ue1) and thereference signal transmit power of the first UE. ρ_(ue1) indicates aratio of energy per resource element EPRE of a physical downlink sharedchannel PDSCH of the first UE to EPRE of a cell-specific referencesignal of the first UE, ρ_(ue1) includes ρ_(A,ue1) and ρ_(B,ue1), andρ_(A,ue1) and ρ_(B,ue1) correspond to different orthogonal frequencydivision multiplexing OFDM symbol indexes of the first UE. For aspecific process for determining ρ_(A,ue1) and ρ_(B,ue1) by theprocessing unit 401, refer to descriptions of the processing unit 302 inEmbodiment 2. Details are not described herein again.

In Embodiment 7 of the present invention, the receiving unit of thefirst UE receives the adjustment parameter δ_(1,ue1), for the firsttransmit power, sent by the base station. The base station schedules thetransmit power by using the adjustment parameter δ_(1,ue1) for the firsttransmit power, so that dynamic scheduling of a transmit power in theNOMA technology is implemented.

Embodiment 8 of the present invention further discloses a first UE. Adifference between Embodiment 8 and Embodiment 6 or Embodiment 7 lies inthat the receiving unit 501 is further configured to receive anadjustment parameter δ_(1,ue2), for the second transmit power, sent bythe base station.

In an optional implementation, the receiving unit 501 is specificallyconfigured to receive the adjustment parameter δ_(1,ue2), for the secondtransmit power, sent by the base station by using higher layer signalingor by using DCI in a PDCCH.

In this embodiment, the processing unit 502 is specifically configuredto determine the second transmit power according to the power parametersof the second UE and the adjustment parameter δ_(1,ue2) for the secondtransmit power.

In an optional implementation, the adjustment parameter δ_(1,ue2) forthe second transmit power is an adjustment value for the second transmitpower. The processing unit 502 is specifically configured to determine afourth transmit power according to the power parameters of the secondUE. The second transmit power is obtained after the adjustment value forthe second transmit power is subtracted from or added to the fourthtransmit power. For a manner of determining the fourth transmit power bythe processing unit 502, refer to processing by the processing unit 401in Embodiment 5. Details are not described herein again.

In an optional implementation, the processing unit 502 is specificallyconfigured to determine ρ_(ue2) according to P_(A,ue) ₂ , P_(B,ue) ₂ ,and the adjustment parameter δ_(1,ue2) for the second transmit power,and determine the second transmit power according to ρ_(ue2) and thereference signal transmit power of the second UE. ρ_(ue2) indicates aratio of energy per resource element EPRE of a physical downlink sharedchannel PDSCH of the second UE to EPRE of a cell-specific referencesignal of the second UE, ρ_(ue2) includes ρ_(A,ue2) and ρ_(B,ue2), andρ_(A,ue2) and ρ_(B,ue2) correspond to different orthogonal frequencydivision multiplexing OFDM symbol indexes of the second UE. For a mannerof determining the second transmit power by the processing unit 502,refer to processing by the processing unit 401 in Embodiment 5. Detailsare not described herein again.

In Embodiment 8 of the present invention, the receiving unit 501 of thefirst UE receives the adjustment parameter δ_(1,ue2), for the secondtransmit power, sent by the base station. The base station schedules thetransmit power by using the adjustment parameter δ_(1,ue2) for thesecond transmit power, so that dynamic scheduling of a transmit power inthe NOMA technology is implemented.

Based on the network architecture shown in FIG. 1, Embodiment 9 of thepresent invention discloses a communication method. The method isapplied to a communications network including at least two userequipments UEs. The at least two UEs include a first UE and a second UE.FIG. 6 is a schematic flowchart of the communication method according toEmbodiment 9 of the present invention. As shown in FIG. 6, thecommunication method may include the following steps.

601. A base station obtains power parameters of the first user equipmentUE and an adjustment parameter δ_(1,ue1) for a first transmit power,where the power parameters of the first UE include a UE-specificparameter P_(A,ue) ₁ of the first UE, a cell-specific parameter P_(B,ue)₁ of the first UE, and a reference signal transmit power of the firstUE, and the first transmit power is a transmit power of downlink datafor the first UE.

602. The base station sends the power parameters of the first UE and theadjustment parameter δ_(1,ue1) for the first transmit power to the firstUE.

603. The base station determines the first transmit power according tothe power parameters of the first UE and the adjustment parameterδ_(1,ue1) for the first transmit power.

604. The base station sends a downlink signal for the first UE at thefirst transmit power.

For meanings of these related parameters in this embodiment of thepresent invention, refer to related descriptions in Embodiment 1.

In an optional implementation, the base station sends the powerparameters of the first UE and the parameter δ_(2,ue1) to the first UEby using higher layer signaling or by using DCI in a PDCCH.

In an optional implementation, the adjustment parameter δ_(1,ue1) forthe first transmit power is an adjustment value for the first transmitpower. The base station determines a third transmit power according tothe power parameters of the first UE. The first transmit power isobtained after the adjustment value for the first transmit power issubtracted from or added to the third transmit power.

In an optional implementation, the base station determines ρ_(ue1)according to P_(A,ue) ₁ and P_(B,ue) ₁ , and determines the thirdtransmit power according to ρ_(ue1) and the reference signal transmitpower of the first UE. ρ_(ue1) indicates a ratio of energy per resourceelement EPRE of a physical downlink shared channel PDSCH of the first UEto EPRE of a cell-specific reference signal of the first UE, ρ_(ue1)includes ρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1) correspondto different orthogonal frequency division multiplexing OFDM symbolindexes of the first UE.

In an optional implementation, when determining the third transmitpower, the base station determines ρ_(A,ue1) according to the followingformulas:

$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The base station determines ρ_(B,ue1) according to ρ_(A,ue1) and Table3.

In an optional implementation, the base station uses a downlink poweroffset field in DCI in a PDCCH of the first UE to indicateδ_(power-offset). The downlink power offset field may occupy one bit.The first UE learns of δ_(power-offset) by using the downlink poweroffset field. For example, the downlink power offset field may be shownin the following Table 4.

In an optional implementation, the base station determines ρ_(ue1)according to P_(A,ue) ₁ , P_(B,ue) ₁ , and the adjustment parameterδ_(1,ue1) for the first transmit power, and determines the firsttransmit power according to ρ_(ue1) and the reference signal transmitpower of the first UE. For meanings of these parameters, refer toEmbodiment 1.

In an optional implementation, the base station determines ρ_(A,ue1)according to the following formulas:

$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The base station determines ρ_(B,ue1) according to ρ_(A,ue1) and Table3.

In another optional implementation, the base station further determinesa second transmit power according to the power parameters of the firstUE and the first transmit power. The second transmit power is a transmitpower of downlink data for the second UE. The base station sends asignal to the second UE at the second transmit power.

In an optional implementation, the base station determines the secondtransmit power according to the third transmit power and the firsttransmit power. The third transmit power is determined according to thepower parameters of the first UE. For a specific implementation ofdetermining, refer to the foregoing descriptions.

In an optional implementation, the second transmit power is a differencebetween the third transmit power and the first transmit power.

In Embodiment 1 of the present invention, the base station obtains theadjustment parameter δ_(1,ue1) for the first transmit power and thepower parameters of the first UE, and sends the adjustment parameterδ_(1,ue1) for the first transmit power and the power parameters of thefirst UE to the first UE. Therefore, the first UE may obtain the firsttransmit power according to the power parameters of the first userequipment UE, and determine the second transmit power according to theadjustment parameter δ_(1,ue1) for the first transmit power and thefirst transmit power. The first UE can eliminate interference from thedownlink data for the second UE according to the second transmit power,to implement communication by using a NOMA technology. In addition, thebase station obtains the adjustment parameter δ_(1,ue1) for the firsttransmit power, and sends the adjustment parameter δ_(1,ue1) for thefirst transmit power to the first UE. The base station schedules thefirst transmit power by using the adjustment parameter δ_(1,ue1) for thefirst transmit power, so that dynamic scheduling of a transmit power inthe NOMA technology is implemented.

An application scenario of Embodiment 9 is consistent with theapplication scenario of Embodiment 1.

Based on the network architecture shown in FIG. 1, Embodiment 10 of thepresent invention discloses a communication method. The method isapplied to a communications network including at least two userequipments UEs. The at least two UEs include a first UE and a second UE.FIG. 7 is a schematic flowchart of the communication method according toEmbodiment 10 of the present invention. As shown in FIG. 7, thecommunication method may include the following steps.

701. The first user equipment UE obtains power parameters of the firstUE and an adjustment parameter δ_(1,ue1) for a first transmit power thatare sent by a base station, where the power parameters of the first UEinclude P_(A,ue) ₁ of the first UE, a cell-specific parameter P_(B,ue) ₁of the first UE, and a reference signal transmit power of the first UE,and the first transmit power is a transmit power of downlink data forthe first UE.

702. The first UE determines the first transmit power according to thepower parameters of the first UE and the adjustment parameter δ_(1,ue1)for the first transmit power.

703. The first UE determines a second transmit power according to thepower parameters of the first UE and the first transmit power, where thesecond transmit power is a transmit power of downlink data for thesecond UE.

704. The first UE receives a signal sent by the base station, where thereceived signal includes the downlink data for the first UE.

705. The first UE obtains the downlink data for the first UE from thereceived signal according to the first transmit power and the secondtransmit power.

For meanings of these related parameters in this embodiment of thepresent invention, refer to Embodiment 1.

In an optional implementation, the first UE receives the powerparameters of the first UE and the adjustment parameter δ_(1,ue1) forthe first transmit power that are sent by the base station by usinghigher layer signaling or by using DCI in a PDCCH.

In an optional implementation, the adjustment parameter δ_(1,ue1) forthe first transmit power is an adjustment value for the first transmitpower. The first UE determines a third transmit power according to thepower parameters of the first UE. The first transmit power is obtainedafter the adjustment value for the first transmit power is subtractedfrom or added to the third transmit power.

In another optional implementation, the first UE determines ρ_(ue1)according to P_(A,ue) ₁ and P_(B,ue) ₁ , and determines the thirdtransmit power according to ρ_(ue1) and the reference signal transmitpower of the first UE. ρ_(ue1) indicates a ratio of energy per resourceelement EPRE of a physical downlink shared channel PDSCH of the first UEto EPRE of a cell-specific reference signal of the first UE, ρ_(ue1)includes ρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1) correspondto different orthogonal frequency division multiplexing OFDM symbolindexes of the first UE. For descriptions of these related parameters,refer to Embodiment 1.

In an optional implementation, when determining the third transmitpower, the first UE determines ρ_(A,ue1) according to the followingformulas:

$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The first UE determines ρ_(B,ue1) according to ρ_(A,ue1) and Table 3.

In an optional implementation, the first UE receives an indicationδ_(power-offset) sent by the base station by using a downlink poweroffset field in DCI in a PDCCH of the first UE. The downlink poweroffset field may occupy one bit. For example, the downlink power offsetfield may be shown in the following Table 4.

In an optional implementation, the first UE determines ρ_(ue1) accordingto P_(A,ue) ₁ , P_(B,ue) ₁ , and the adjustment parameter δ_(1,ue1) forthe first transmit power, and determines the first transmit poweraccording to ρ_(ue1) and the reference signal transmit power of thefirst UE. ρ_(ue1) indicates a ratio of energy per resource element EPREof a physical downlink shared channel PDSCH of the first UE to EPRE of acell-specific reference signal of the first UE, ρ_(ue1) includesρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1) correspond todifferent orthogonal frequency division multiplexing OFDM symbol indexesof the first UE.

In an optional implementation, the first UE determines ρ_(A,ue1)according to the following formulas:

$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The first UE determines ρ_(B,ue1) according to ρ_(A,ue1) and Table 3.

In an optional implementation, the first UE determines the secondtransmit power according to the power parameters of the first UE and thefirst transmit power. The second transmit power is the transmit power ofthe downlink data for the second UE.

In an optional implementation, the first UE determines the secondtransmit power according to the third transmit power and the firsttransmit power. The third transmit power is determined according to thepower parameters of the first UE. For a specific implementation ofdetermining, refer to the foregoing descriptions.

In an optional implementation, the second transmit power is a differencebetween the third transmit power and the first transmit power.

In Embodiment 10 of the present invention, the first UE receives thepower parameters of the first UE and the adjustment parameter δ_(1,ue1)for the first transmit power that are sent by the base station. Thefirst UE obtains the first transmit power according to the powerparameters of the first user equipment UE, and determines the secondtransmit power according to the power parameters of the first UE and thefirst transmit power. The first UE can eliminate interference from asignal for the second UE according to the second transmit power, toimplement communication by using a NOMA technology.

An application scenario of Embodiment 10 is consistent with theapplication scenario of Embodiment 2.

Based on the network architecture shown in FIG. 1, Embodiment 11 of thepresent invention discloses a communication method. The method isapplied to a communications network including at least two userequipments UEs. The at least two UEs include a first UE and a second UE.FIG. 8 is a schematic flowchart of the communication method according toEmbodiment 11 of the present invention. As shown in FIG. 8, thecommunication method may include the following steps.

801. A base station obtains power parameters of the first user equipmentUE and power parameters of the second UE, where the power parameters ofthe first UE include a UE-specific parameter P_(A,ue) ₁ of the first UE,a cell-specific parameter P_(B,ue) ₁ of the first UE, and a referencesignal transmit power of the first UE, and the power parameters of thesecond UE include a UE-specific parameter P_(A,ue) ₂ of the second UE, acell-specific parameter P_(B,ue2) of the second UE, and a referencesignal transmit power of the second UE.

802. The base station sends the power parameters of the first UE and thepower parameters of the second UE to the first UE.

803. The base station determines a first transmit power according to thepower parameters of the first UE, where the first transmit power is atransmit power of downlink data for the first UE.

804. The base station sends the downlink data for the first UE at thefirst transmit power.

For meanings of these related parameters in this embodiment of thepresent invention, refer to Embodiment 3.

In an optional implementation, the base station sends the powerparameters of the first UE and the power parameters of the second UE tothe first UE by using higher layer signaling or by using DCI in a PDCCH.

In an optional implementation, the base station determines ρ_(ue1)according to P_(A,ue) ₁ and P_(B,ue) ₁ , and determines the firsttransmit power according to ρ_(ue1) and the reference signal transmitpower of the first UE.

In an optional implementation, the base station determines ρ_(A,ue1)according to the following formulas:

$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + P_{A,{{ue}\; 1}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The base station determines ρ_(B,ue1) according to ρ_(A,ue1) and Table3.

In an optional implementation, the base station uses a downlink poweroffset field in DCI in a PDCCH of the first UE to indicateδ_(power-offset). The downlink power offset field may occupy one bit.The first UE learns of δ_(power-offset) by using the downlink poweroffset field. For example, the downlink power offset field may be shownin the following Table 4.

In an optional implementation, the base station determines a secondtransmit power according to the power parameters of the second UE. Thesecond transmit power is a transmit power of downlink data for thesecond UE. The base station sends the downlink data for the second UE atthe second transmit power.

In an optional implementation, the base station determines ρ_(ue2)according to P_(A,ue) ₂ and P_(B,ue2), and determines the secondtransmit power according to ρ_(ue2) and the reference signal transmitpower of the second UE. ρ_(ue2) indicates a ratio of energy per resourceelement EPRE of a physical downlink shared channel PDSCH of the secondUE to EPRE of a cell-specific reference signal of the second UE, ρ_(ue2)includes ρ_(A,ue2) and ρ_(B,ue2), and ρ_(A,ue2) and ρ_(B,ue2) correspondto different orthogonal frequency division multiplexing OFDM symbolindexes of the second UE.

In an optional implementation, the OFDM symbol indexes corresponding toρ_(A,ue2) and ρ_(B,ue2) are shown in Table 5 or Table 6.

In an optional implementation, the base station determines ρ_(A,ue2)according to the following formulas:

$\rho_{A,{{ue}\; 2}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + P_{A,{{ue}\; 2}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + P_{A,{{ue}\; 2}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The base station determines ρ_(B,ue2) according to ρ_(A,ue2) and Table3.

In this embodiment of the present invention, the base station obtainsthe power parameters of the first UE and the power parameters of thesecond UE, and sends the power parameters of the first UE and the powerparameters of the second UE to the first UE, so that the first UE mayobtain the first transmit power according to the power parameters of thefirst UE, and determine the second transmit power according to the powerparameters of the second UE. The first UE can eliminate interferencefrom a signal for the second UE according to the second transmit power,to implement communication by using a NOMA technology.

An application scenario of Embodiment 11 is consistent with theapplication scenario of Embodiment 1.

Based on the network architecture shown in FIG. 1, Embodiment 12 of thepresent invention discloses a communication method. A difference betweenEmbodiment 12 and Embodiment 11 lies in that the base station furtherobtains an adjustment parameter δ_(1,ue1) for the first transmit power,and sends the adjustment parameter δ_(1,ue1) for the first transmitpower to the first UE. For meanings of these related parameters, referto Embodiment 1.

In an optional implementation, the base station sends the adjustmentparameter δ_(1,ue1) for the first transmit power to the first UE byusing higher layer signaling or by using DCI in a PDCCH.

In this embodiment, the base station determines the first transmit poweraccording to the power parameters of the first UE and the adjustmentparameter δ_(1,ue1) for the first transmit power.

In an optional implementation, the adjustment parameter δ_(1,ue1) forthe first transmit power is an adjustment value for the first transmitpower. The base station determines a third transmit power according tothe power parameters of the first UE. The first transmit power isobtained after the adjustment value for the first transmit power issubtracted from or added to the third transmit power. For a manner ofdetermining the third transmit power by the base station, refer toprocessing in Embodiment 9. Details are not described herein again.

In an optional implementation, the base station determines ρ_(ue1)according to P_(A,ue) ₁ , P_(B,ue) ₁ and the adjustment parameterδ_(1,ue1) for the first transmit power, and determines the firsttransmit power according to ρ_(ue1) and the reference signal transmitpower of the first UE. ρ_(ue1) indicates a ratio of energy per resourceelement EPRE of a physical downlink shared channel PDSCH of the first UEto EPRE of a cell-specific reference signal of the first UE, ρ_(ue1)includes ρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1) correspondto different orthogonal frequency division multiplexing OFDM symbolindexes of the first UE. For a specific process for determiningρ_(A,ue1) and ρ_(B,ue1) by the base station, refer to descriptions inEmbodiment 9.

In this embodiment of the present invention, the base station obtainsthe adjustment parameter δ_(1,ue1) for the first transmit power, andsends the adjustment parameter δ_(1,ue1) for the first transmit power tothe first UE. The base station schedules the first transmit power byusing the adjustment parameter δ_(1,ue1) for the first transmit power,so that dynamic scheduling of a transmit power in a NOMA technology isimplemented.

Embodiment 13 of the present invention further discloses a base station.A difference between Embodiment 13 and Embodiment 11 or Embodiment 12lies in that the base station further obtains an adjustment parameterδ_(1,ue2) for the second transmit power, and further sends theadjustment parameter δ_(1,ue2) for the second transmit power to thefirst UE.

In an optional implementation, the base station sends the adjustmentparameter δ_(1,ue2) for the second transmit power to the first UE byusing higher layer signaling or by using DCI in a PDCCH.

In an optional implementation, the base station determines the secondtransmit power according to the power parameters of the second UE andthe adjustment parameter δ_(1,ue2) for the second transmit power, and isfurther configured to send the downlink data for the second UE at thesecond transmit power.

In an optional implementation, the adjustment parameter δ_(1,ue2) forthe second transmit power is an adjustment value for the second transmitpower. The base station determines a fourth transmit power according tothe power parameters of the second UE. The second transmit power isobtained after the adjustment value for the second transmit power issubtracted from or added to the fourth transmit power.

In an optional implementation, the base station determines ρ_(ue2)according to P_(A,ue2) and P_(B,ue2) and determines the fourth transmitpower according to ρ_(ue2) and the reference signal transmit power ofthe second UE. ρ_(ue2) indicates a ratio of energy per resource elementEPRE of a physical downlink shared channel PDSCH of the second UE toEPRE of a cell-specific reference signal of the second UE, ρ_(ue2)includes ρ_(A,ue2) and ρ_(B,ue2), and ρ_(A,ue2) and ρ_(B,ue2) correspondto different orthogonal frequency division multiplexing OFDM symbolindexes of the second UE.

In an optional implementation, for meanings of ρ_(A,ue2) and ρ_(B,ue2)for determining the fourth transmit power, refer to Embodiment 11. For adetermining manner of ρ_(A,ue2) and ρ_(B,ue2), refer to descriptions inEmbodiment 11. Details are not described herein again.

In another optional implementation, the base station determines ρ_(ue2)according to P_(A,ue) ₂ , P_(B,ue) ₂ , and the adjustment parameterδ_(1,ue2) for the second transmit power, and determines the secondtransmit power according to ρ_(ue2) and the reference signal transmitpower of the second UE. ρ_(ue2) indicates a ratio of energy per resourceelement EPRE of a physical downlink shared channel PDSCH of the secondUE to EPRE of a cell-specific reference signal of the second UE, ρ_(ue2)includes ρ_(A,ue2) and ρ_(B,ue2), and ρ_(A,ue2) and ρ_(B,ue2) correspondto different orthogonal frequency division multiplexing OFDM symbolindexes of the second UE.

In an implementation, the base station determines ρ_(A,ue2) according tothe following formulas:

$\rho_{A,{{ue}\; 2}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + \delta_{1,{{ue}\; 2}} + P_{A,{{ue}\; 2}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + \delta_{1,{{ue}\; 2}} + P_{A,{{ue}\; 2}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ {\begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix}.} \right.} \right.$

The base station determines ρ_(B,ue2) according to ρ_(A,ue2) and Table3.

In Embodiment 13 of the present invention, the base station obtains theadjustment parameter δ_(1,ue2) for the second transmit power, and sendsthe adjustment parameter δ_(1,ue2) for the second transmit power to thefirst UE. The base station schedules the transmit power by using theadjustment parameter δ_(1,ue2) for the second transmit power, so thatdynamic scheduling of a transmit power in a NOMA technology isimplemented.

Based on the network architecture shown in FIG. 1, Embodiment 14 of thepresent invention discloses a communication method. The method isapplied to a communications network including at least two userequipments UEs. The at least two UEs include a first UE and a second UE.FIG. 9 is a schematic flowchart of the communication method according toEmbodiment 14 of the present invention. As shown in FIG. 9, thecommunication method may include the following steps.

901. The first UE receives power parameters of the first UE and powerparameters of the second UE that are sent by a base station, where thepower parameters of the first UE include a UE-specific parameterP_(A,ue) ₁ of the first UE, a cell-specific parameter P_(B,ue) ₁ of thefirst UE, and a reference signal transmit power of the first UE, and thepower parameters of the second UE include a UE-specific parameterP_(A,ue) ₂ of the second UE, a cell-specific parameter P_(B,ue2) of thesecond UE, and a reference signal transmit power of the second UE.

902. The first UE determines a first transmit power according to thepower parameters of the first UE, where the first transmit power is atransmit power of downlink data for the first UE.

903. Determines a second transmit power according to the powerparameters of the second UE, where the second transmit power is atransmit power of downlink data for the second UE.

904. The first UE receives a signal sent by the base station, where thereceived signal includes the downlink data for the first UE.

905. The first UE obtains the downlink data for the first UE from thereceived signal according to the first transmit power and the secondtransmit power.

In an optional implementation, the first UE receives the powerparameters of the first UE and the power parameters of the second UEthat are sent by the base station by using higher layer signaling or byusing DCI in a PDCCH.

In an optional implementation, the first UE determines ρ_(ue1) accordingto P_(A,ue) ₁ and P_(B,ue) ₁ , and determines the first transmit poweraccording to ρ_(ue1) and the reference signal transmit power of thefirst UE. ρ_(ue1) indicates a ratio of energy per resource element EPREof a physical downlink shared channel PDSCH of the first UE to EPRE of acell-specific reference signal of the first UE, ρ_(ue1) includesρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1) correspond todifferent orthogonal frequency division multiplexing OFDM symbol indexesof the first UE. A specific process is the same as the manner fordetermining the first transmit power by the base station in Embodiment8. For corresponding descriptions, refer to Embodiment 8. Details arenot described herein again.

The first UE determines the second transmit power according to the powerparameters of the second UE.

In an optional implementation, the first UE determines ρ_(ue2) accordingto P_(A,ue2) and P_(B,ue2), and determines the second transmit poweraccording to ρ_(ue2) and the reference signal transmit power of thesecond UE. ρ_(ue2) indicates a ratio of energy per resource element EPREof a physical downlink shared channel PDSCH of the second UE to EPRE ofa cell-specific reference signal of the second UE, ρ_(ue2) includesρ_(A,ue2) and ρ_(B,ue2), and ρ_(A,ue2) and ρ_(B,ue2) correspond todifferent orthogonal frequency division multiplexing OFDM symbol indexesof the second UE. A specific process is the same as the manner fordetermining the second transmit power by the base station in Embodiment8. For corresponding descriptions, refer to Embodiment 8. Details arenot described herein again.

In Embodiment 6 of the present invention, the receiving unit of thefirst UE receives the power parameters of the first UE and the powerparameters of the second UE that are sent by the base station. Theprocessing unit of the first UE may obtain the first transmit poweraccording to the power parameters of the first UE, and determine thesecond transmit power according to the power parameters of the secondUE. The first UE can eliminate interference from the downlink data forthe second UE according to the second transmit power, to implementcommunication by using a NOMA technology.

Embodiment 15 of the present invention further discloses a first UE. Adifference between Embodiment 15 and Embodiment 14 lies in that thefirst UE receives an adjustment parameter δ_(1,ue1), for the firsttransmit power, sent by the base station. The first UE determines thefirst transmit power according to the power parameters of the first UEand the adjustment parameter δ_(1,ue1) for the first transmit power.

In an optional implementation, the first UE receives the adjustmentparameter δ_(1,ue1), for the first transmit power, sent by the basestation by using higher layer signaling or by using downlink controlinformation DCI in a physical downlink control channel PDCCH.

In an optional implementation, the adjustment parameter δ_(1,ue1) forthe first transmit power is an adjustment value for the first transmitpower. The first UE determines a third transmit power according to thepower parameters of the first UE. The first transmit power is obtainedafter the adjustment value for the first transmit power is subtractedfrom or added to the third transmit power. For a manner of determiningthe third transmit power by the first UE, refer to processing inEmbodiment 10. Details are not described herein again.

In an optional implementation, the first UE determines ρ_(ue1) accordingto P_(A,ue) ₁ , P_(B,ue) ₁ , and the adjustment parameter δ_(1,ue1) forthe first transmit power, and determines the first transmit poweraccording to ρ_(ue1) and the reference signal transmit power of thefirst UE. ρ_(ue1) indicates a ratio of energy per resource element EPREof a physical downlink shared channel PDSCH of the first UE to EPRE of acell-specific reference signal of the first UE, ρ_(ue1) includesρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1) correspond todifferent orthogonal frequency division multiplexing OFDM symbol indexesof the first UE. For a specific process for determining ρ_(A,ue1) andρ_(B,ue1) by the first UE, refer to descriptions in Embodiment 10.Details are not described herein again.

In Embodiment 15 of the present invention, the receiving unit of thefirst UE receives the adjustment parameter δ_(1,ue1), for the firsttransmit power, sent by the base station. The base station schedules thetransmit power by using the adjustment parameter δ_(1,ue1) for the firsttransmit power, so that dynamic scheduling of a transmit power in a NOMAtechnology is implemented.

Embodiment 16 of the present invention further discloses a first UE. Adifference between Embodiment 16 and Embodiment 14 or Embodiment 15 liesin that the first UE receives an adjustment parameter δ_(1,ue2), for thesecond transmit power, sent by the base station.

In an optional implementation, the first UE receives the adjustmentparameter δ_(1,ue2), for the second transmit power, sent by the basestation by using higher layer signaling or by using DCI in a PDCCH.

In this embodiment, the first UE determines the second transmit poweraccording to the power parameters of the second UE and the adjustmentparameter δ_(1,ue2) for the second transmit power.

In an optional implementation, the adjustment parameter δ_(1,ue2) forthe second transmit power is an adjustment value for the second transmitpower. The first UE determines a fourth transmit power according to thepower parameters of the second UE. The second transmit power is obtainedafter the adjustment value for the second transmit power is subtractedfrom or added to the fourth transmit power. For a manner of determiningthe fourth transmit power by the first UE, refer to processing inEmbodiment 13. Details are not described herein again.

In an optional implementation, the first UE determines ρ_(ue2) accordingto P_(A,ue) ₂ , P_(B,ue) ₂ and the adjustment parameter δ_(1,ue2) forthe second transmit power, and determines the second transmit poweraccording to ρ_(ue2) and the reference signal transmit power of thesecond UE. ρ_(ue2) indicates a ratio of energy per resource element EPREof a physical downlink shared channel PDSCH of the second UE to EPRE ofa cell-specific reference signal of the second UE, ρ_(ue2) includesρ_(A,ue2) and ρ_(B,ue2), and ρ_(A,ue2) and ρ_(B,ue2) correspond todifferent orthogonal frequency division multiplexing OFDM symbol indexesof the second UE. For a manner of determining the second transmit powerby the first UE, refer to processing in Embodiment 13. Details are notdescribed herein again.

In Embodiment 16 of the present invention, the first UE receives theadjustment parameter δ_(1,ue2), for the second transmit power, sent bythe base station. The base station schedules the transmit power by usingthe adjustment parameter δ_(1,ue2) for the second transmit power, sothat dynamic scheduling of a transmit power in a NOMA technology isimplemented.

In the several embodiments provided in this application, it should beunderstood that the disclosed apparatus and method may be implemented inother manners. For example, the described apparatus embodiment is merelyan example. For example, the unit division is merely logical functiondivision and may be other division in actual implementation. Forexample, multiple units or components may be combined or integrated intoanother system, or some features may be ignored or not performed. Inaddition, the displayed or discussed mutual couplings or directcouplings or communication connections may be implemented through someinterfaces, indirect couplings or communication connections between theapparatuses or units, or electrical connections, mechanical connections,or connections in other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on multiplenetwork units. Some or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of the presentinvention may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of a software functional unit.

When the integrated unit is implemented in the form of a softwarefunctional unit and sold or used as an independent product, theintegrated unit may be stored in a computer-readable storage medium.Based on such an understanding, the technical solutions of the presentinvention essentially, or the part contributing to the prior art, or allor some of the technical solutions may be implemented in the form of asoftware product. The software product is stored in a storage medium andincludes several instructions for instructing a computer device (whichmay be a personal computer, a server, or a network device) to performall or some of the steps of the methods described in the embodiments ofthe present invention. The foregoing storage medium includes: any mediumthat can store program code, such as a USB flash drive, a removable harddisk, a read-only memory (ROM), a random access memory (RAM), a magneticdisk, or an optical disc.

The foregoing descriptions are merely specific implementations of thepresent invention, but are not intended to limit the protection scope ofthe present invention. Any variation or replacement readily figured outby a person skilled in the art within the technical scope disclosed inthe present invention shall fall within the protection scope of thepresent invention. Therefore, the protection scope of the presentinvention shall be subject to the protection scope of the claims.

What is claimed is:
 1. A base station to serve at least two userequipments (UEs) comprising a first UE and a second UE, and the basestation comprising: a processor, configured to obtain power parametersof the first UE and an adjustment parameter δ_(1,ue1) for a firsttransmit power, wherein the power parameters of the first UE comprise aUE-specific parameter P_(A,ue) ₁ of the first UE, a cell-specificparameter P_(B,ue) ₁ of the first UE, and a reference signal transmitpower of the first UE, and the first transmit power is a transmit powerof downlink data for the first UE; and a transmitter, configured to sendthe power parameters of the first UE and the adjustment parameterδ_(1,ue1) for the first transmit power to the first UE; wherein theprocessor is further configured to: determine the first transmit poweraccording to the power parameters of the first UE and the adjustmentparameter δ_(1,ue1) for the first transmit power, and determine ρ_(ue1)according to P_(A,ue) ₁ , P_(B,ue) ₁ , and the adjustment parameterδ_(1,ue1) for the first transmit power, and determine the first transmitpower according to ρ_(ue1) and the reference signal transmit power ofthe first UE, wherein ρ_(ue1) indicates a ratio of energy per resourceelement (EPRE) of a physical downlink shared channel (PDSCH) of thefirst UE to EPRE of a cell-specific reference signal of the first UE,ρ_(ue1) comprises ρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1)correspond to different orthogonal frequency division multiplexing(OFDM) symbol indexes of the first UE; and the transmitter is furtherconfigured to send the downlink data for the first UE at the firsttransmit power.
 2. The base station according to claim 1, wherein theadjustment parameter δ_(1,ue1) for the first transmit power is anadjustment value for the first transmit power.
 3. The base stationaccording to claim 1, wherein the processor is configured to determineρ_(A,ue1) according to the following formulas:$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + \delta_{1,{{ue}\; 1}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + \delta_{1,{ue1}} + P_{A,{{ue}\; 1}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ \begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix} \right.} \right.$ and the processor is configured todetermine ρ_(B,ue1) according to ρ_(A,ue1) and the following table:ρ_(B,ue1)/ρ_(A,ue1) P_(B,ue1) One antenna port Two or four antenna ports0 1 5/4 1 4/5 1 2 3/5 3/4 3 2/5 1/2.


4. The base station according to claim 1, wherein the processor isfurther configured to determine a second transmit power according to thepower parameters of the first UE and the first transmit power, whereinthe second transmit power is a transmit power of downlink data for thesecond UE; and the transmitter is further configured to send thedownlink data for the second UE at the second transmit power.
 5. Acommunication method applied to a communications network comprising atleast two user equipments (UEs) comprising a first UE and a second UE,and the method comprising: obtaining, by a base station, powerparameters of the first user equipment UE and an adjustment parameterδ_(1,ue1) for a first transmit power, wherein the power parameters ofthe first UE comprise a UE-specific parameter P_(A,ue) ₁ of the firstUE, a cell-specific parameter P_(B,ue) ₁ of the first UE, and areference signal transmit power of the first UE, and the first transmitpower is a transmit power of downlink data for the first UE; sending, bythe base station, the power parameters of the first UE and theadjustment parameter δ_(1,ue1) for the first transmit power to the firstUE; determining, by the base station, the first transmit power accordingto the power parameters of the first UE and the adjustment parameterδ_(1,ue1) for the first transmit power, wherein the determining, by thebase station, the first transmit power according to the power parametersof the first UE and the adjustment parameter δ_(1,ue1) for the firsttransmit power comprises: determining, by the base station, ρ_(ue1)according to P_(A,ue) ₁ , P_(B,ue) ₁ , and the adjustment parameterδ_(1,ue1) for the first transmit power, and determining the firsttransmit power according to ρ_(ue1) and the reference signal transmitpower of the first UE; wherein ρ_(ue1) indicates a ratio of energy perresource element (EPRE) of a physical downlink shared channel (PDSCH) ofthe first UE to EPRE of a cell-specific reference signal of the firstUE; ρ_(ue1) comprises ρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) andρ_(B,ue1) correspond to different orthogonal frequency divisionmultiplexing (OFDM) symbol indexes of the first UE; and sending, by thebase station, a downlink signal for the first UE at the first transmitpower.
 6. The method according to claim 5, wherein the adjustmentparameter δ_(1,ue1) for the first transmit power is an adjustment valuefor the first transmit power.
 7. The method according to claim 5,wherein the determining, by the base station, ρ_(ue1) according toP_(A,ue) ₁ , P_(B,ue) ₁ and the adjustment parameter δ_(1,ue1) for thefirst transmit power comprises: determining, by the base station,ρ_(A,ue1) according to the following formulas:$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + \delta_{1,{{ue}\; 1}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + \delta_{1,{{ue}\; 1}} + P_{A,{{ue}\; 1}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ \begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix} \right.} \right.$ and determining, by the base station,ρ_(B,ue1) according to ρ_(A,ue1) and the following table:ρ_(B,ue1)/ρ_(A,ue1) P_(B,ue1) One antenna port Two or four antenna ports0 1 5/4 1 4/5 1 2 3/5 3/4 3 2/5 1/2.


8. The method according to claim 5, further comprising: determining, bythe base station, a second transmit power according to the powerparameters of the first UE and the first transmit power, wherein thesecond transmit power is a transmit power of downlink data for thesecond UE; and sending, by the base station, the downlink data for thesecond UE at the second transmit power.
 9. A first user equipment (UE)to communicate with a base station, the base station serves at least twoUEs, the at least two UEs comprise the first UE and a second UE, and thefirst UE comprising: a receiver, configured to receive power parametersof the first UE and an adjustment parameter δ_(1,ue1) for a firsttransmit power that are sent by the base station, wherein the powerparameters of the first UE comprise P_(A,ue) ₁ of the first UE, acell-specific parameter P_(B,ue) ₁ of the first UE, and a referencesignal transmit power of the first UE, and the first transmit power is atransmit power of downlink data for the first UE; and a processor,configured to: determine the first transmit power according to the powerparameters of the first UE and the adjustment parameter δ_(1,ue1) forthe first transmit power, determine a second transmit power according tothe power parameters of the first UE and the first transmit power,wherein the second transmit power is a transmit power of downlink datafor the second UE, and determine ρ_(ue1) according to P_(A,ue) ₁ ,P_(B,ue) ₁ and the adjustment parameter δ_(1,ue1) for the first transmitpower, and determine the first transmit power according to ρ_(ue1) andthe reference signal transmit power of the first UE, wherein ρ_(ue1)indicates a ratio of energy per resource element (EPRE) of a physicaldownlink shared channel (PDSCH) of the first UE to EPRE of acell-specific reference signal of the first UE, ρ_(ue1) comprisesρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1) correspond todifferent orthogonal frequency division multiplexing (OFDM) symbolindexes of the first UE; wherein the receiver is further configured toreceive a signal sent by the base station, wherein the received signalcomprises the downlink data for the first UE; and the processor isfurther configured to obtain, according to the first transmit power andthe second transmit power, the downlink data for the first UE from thesignal received by the receiver.
 10. The first UE according to claim 9,wherein the adjustment parameter δ_(1,ue1) for the first transmit poweris an adjustment value for the first transmit power.
 11. The first UEaccording to claim 9, wherein the processor is configured to determineρ_(A,ue1) according to the following formulas:$\rho_{A,{{ue}\; 1}} = \left\{ {{\begin{matrix}{\delta_{{power} - {offset}} + \delta_{1,{ue1}} + P_{A,{{ue}\; 1}} + {10{\log_{10}(2)}}} & \underset{{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}} \\{\delta_{{power} - {offset}} + \delta_{1,{{ue}\; 1}} + P_{A,{{ue}\; 1}}} & \underset{{antenna}\mspace{14mu}{ports}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}{{when}\mspace{14mu}{transmit}\mspace{14mu}{diversity}\mspace{14mu}{based}\mspace{14mu}{on}\mspace{14mu}{four}}\end{matrix}\delta_{{power} - {offset}}} = \left\{ \begin{matrix}{{- 10}\;{\log_{10}(2)}} & {{{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}};} \\{0\mspace{14mu}{dB}} & {{when}\mspace{14mu}{multi}\text{-}{user}\mspace{14mu}{MU}\text{-}{MIMO}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{used}\mspace{14mu}{for}\mspace{14mu}{transmission}}\end{matrix} \right.} \right.$ and the processor is configured todetermine ρ_(B,ue1) according to ρ_(A,ue1) and the following table:ρ_(B,ue1)/ρ_(A,ue1) P_(B,ue1) One antenna port Two or four antenna ports0 1 5/4 1 4/5 1 2 3/5 3/4 3 2/5 1/2.


12. The first UE according to claim 9, wherein the processor isconfigured to: determine a third transmit power according to the powerparameters of the first UE, and determine the second transmit poweraccording to the third transmit power and the first transmit power. 13.The first UE according to claim 12, wherein the second transmit power isa difference between the third transmit power and the first transmitpower.
 14. The first UE according to claim 12, wherein the processor isspecifically configured to: determine ρ_(ue1) according to P_(A,ue) ₁and P_(B,ue) ₁ , and determine the first transmit power according toρ_(ue1) and the reference signal transmit power of the first UE, whereinρ_(ue1) indicates a ratio of energy per resource element (EPRE) of aphysical downlink shared channel (PDSCH) of the first UE to EPRE of acell-specific reference signal of the first UE, ρ_(ue1) comprisesρ_(A,ue1) and ρ_(B,ue1), and ρ_(A,ue1) and ρ_(B,ue1) correspond todifferent orthogonal frequency division multiplexing (OFDM) symbolindexes of the first UE.